Thank you คนถางทาง

จังกอบ may be of chinese origin.

from wikipedia : Junk is a type of chinese boat

EtymologyThe term ultimately stems from the Chinese chuán (船, "boat; ship"), also based on and pronounced as [dzuːŋ] (Pe̍h-ōe-jī: chûn) in the Min Nan dialect (閩南語), or zhōu 舟, the old word for a sailing vessel.[citation needed] It entered the English language in the 17th century through the Portuguese junco from the Javanese djong.[1] The modern Standard Chinese word for an ocean-going vessel is cáo (艚).

But "junco" period (17C) is not old enough to be in Sukhothai period (12C). So, I need older record. ;(